Title:
POLYFORMAL RESIN, ITS PREPARATION AND RAW MATERIAL FOR OPTICAL INSTRUMENT COMPRISING SAME
Document Type and Number:
Japanese Patent JPH04142331
Kind Code:
A
Abstract:
PURPOSE:To produce a specified polyformal resin excellent in properties such as heat resistance, moldability and optical properties at good efficiency by reacting a specified dihydric phenol with a methylene dihalide in the presence of an alkali in a solvent. CONSTITUTION:A dihydric phenol of formula I [wherein R<1> and R<2> are each 1-6C alkyl; W is a single bond or a group of formula II (wherein R<3> and R<4> are each H, 1-6 C alkyl or 6-12 C aryl) or formula III (wherein n is 4-8)] [e.g. 1-phenyl-1,1-bis(2-methyl-5-isopropyl-4-hydroxyphenyl)methane] is reacted with a methylene dihalide (desirably methylene chloride) in the presence of an alkali (e.g. NaOH) in a solvent (e.g. N-methylpyrrolidone) to obtain a polyformal resin comprising repeating units of formula TV (wherein R<1>, R<2> and W are as defined above) and having a reduced viscosity (as measured in a solution in methylene chloride solvent in a concentration of 0.5g/dl at 20 deg.C) of 0.3dl/g or above (e.g. a resin comprising units repeating of formula V). According to the above process, a polyformal resin excellent in properties such as heat resistance, moldability and optical properties can be obtained at good efficiency.
Inventors:
SHIGEMATSU KAZUYOSHI
TOGAWA FUSASHI
TOGAWA FUSASHI
Application Number:
JP26311490A
Publication Date:
May 15, 1992
Filing Date:
October 02, 1990
Export Citation:
Assignee:
IDEMITSU KOSAN CO
International Classes:
G02B1/04; C08G65/40; (IPC1-7): C08G65/40; G02B1/04
Attorney, Agent or Firm:
Toro Kubota